I've had perhaps too much time over the last couple of days, and have managed to create a Google Earth map of all of the Caltex, BP and Shell service stations in Australia (4,335 service stations in total). The map is attached to this post (if I've done it right).
For the BP and Caltex service stations, clicking on the location will give you the full street address along with a list of types of fuel available, opening hours, whether or not they have EFTPOS and/or an ATM. The BP service stations also include information about the amenities available (eg cafe, restaurant, toilets, etc) - see the first screen shot for an example. Unfortunately Shell don't provide any of this information in their downloadable GPS data - not even the street address - so I haven't been able to include that for Shell service stations.
You'll need Google Earth in order to open the map (too many locations for Google Maps online to handle) - once that's installed on your computer, simply download the file attached, unzip it, and double-click on the "Servos.kml" file to open it in Google Earth. You can then select to show either all BP, Caltex and Shell servos, or switch each individual chain on or off.
You can then take the following steps to save it into your "My Places" in Google Earth so that it's available whenever you need it:
1. In Google Earth, find the "Places" tab (shown on the left hand side of my screen in the second screen shot above)
2. Expand the "Temporary Places" folder, then the "Servos.kml" folder within it.
3. Click and drag the "Servos" folder from within the "Servos.kml" folder into your desired location within the "My Places" folder further up the list.
4. Click File > Save > Save My Places.
It's based on GPS data which you can download from the respective operators' websites, which I've then compiled together and converted into a format Google Maps & Earth can read. Please note however that the locations are therefore only as accurate as the information on the operators' websites as of yesterday (15 January 2013) - any service stations which open after that date won't be in the map, and any which close after that date will still be shown on the map.
I hope some of you find this useful - it took a bit of mucking around to make it all work properly.
Please let me know if you do download and use this map to plan rides - if many people end up using it I'll do an update every 6 months or so to keep the locations accurate.